U.S. Pat. No. 3,308,078 to Rogers et al. generally relates to coating compositions, to methods of applying such coating compositions to substrates to produce films thereon, and to methods of removing such films from such substrates. These coating compositions, more particularly, are said to contain a polymer, a resin, and a metal-containing complex.
U.S. Pat. No. 3,320,196 (also to Rogers) similarly relates to coating compositions, to methods of applying such coating compositions to substrates to produce films thereon, and to methods of removing such films from such substrates. The various coating compositions of the '196 Rogers patent, more particularly, are said to contain a polymer, a resin, and a zirconyl-containing complex.
U.S. Pat. No. 3,679,592 to Schomburg discloses certain compositions that are said to consist of a film-forming component, a surfactant, a scale inhibitor, an organic solvent, and water. Such compositions are said to be effective for cleansing so-called "hard" surfaces and for otherwise inhibiting the deposition of soils or stains onto such surfaces.
In U.S. Pat. Nos. 3,886,125 and 3,966,902, both to Chromecek, certain polymer complexes are disclosed. Such polymer complexes are said to be composed of a polymer that contains hydrophilic functional groups as well as certain metals bound in complex form. Such polymer complexes are said to be prepared by contacting a reaction mixture which contains the functional group-containing polymer, or the monomeric precursor thereof, with a salt of a particular metal, for purposes of complexing such a metal.
In U.S. Pat. Nos. 3,515,579 and 3,635,756, both to Shepherd et al., there are disclosed certain so-called "nonfogging" coatings that are said to be so specifically formulated as to be able to be applied onto transparent or reflective substrates which are normally subject to fogging. In U.S. Pat. No. 3,933,407 to Tu et al., moreover yet another so-called "anti-fog" coating, which is based upon inclusion of a siloxane-oxyalkylene block copolymer, is disclosed.
Such coatings are specifically formulated to provide permanent films on a substrate. For example, one stated object of the '579 Shepherd patent is to provide a coating that "is resistant to ammonia and common alkaline cleaning preparations". In this regard, the polymeric coatings disclosed in the '756 Shepherd patent, furthermore, are touted as being "solvent resistant". Still further, the coatings disclosed in the '407 Tu patent, in addition to being generally described as "solvent resistant", are said to be useful for purposes of imparting "resistance to ammonia and other common alkaline cleaning preparations".
For a variety of reasons, however, it would be desirable to be able to readily remove a variety of substrate-applied coatings--such as anti-fog coatings and other types of coatings--from various substrates, whenever desired.